Dilution mechanism, particle size distribution measurement system, particle size distribution measurement method, and program for particle size distribution measurement

Abstract

A dilution mechanism includes: a sample line that guides the sample containing the particles to the particle size distribution measurement device; a dilution line that merges with the sample line and through which a diluent flows; a concentration adjusting unit that adjusts the concentration of the particles contained in the diluted sample; a conductivity measuring unit that measures a conductivity of the diluted sample; a control unit that controls the concentration adjusting unit to bring the conductivity measured by the conductivity measuring unit or a conductivity-related value that is a value calculated from the conductivity, to a predetermined target value.

1 . A dilution mechanism used with a particle size distribution measurement device that measures a particle size distribution using a dynamic light scattering technique, the dilution mechanism comprising:
 a sample line that guides a sample containing particles to the particle size distribution measurement device;   a dilution line that merges with the sample line and through which a diluent flows;   a concentration adjusting unit that adjusts a concentration of particles contained in diluted sample;   a conductivity measuring unit that measures a conductivity of the diluted sample; and   a control unit that controls the concentration adjusting unit to bring the conductivity measured by the conductivity measuring unit or to bring a conductivity-related value that is a value calculated from the conductivity, to a predetermined target value.   
     
     
         2 . The dilution mechanism according to  claim 1 , further comprising a concentration calculation unit that calculates a concentration of the particles in the diluted sample as the conductivity-related value, from the conductivity measured by the conductivity measuring unit, wherein
 the control unit controls the concentration adjusting unit to bring the concentration calculated by the concentration calculation unit to the target value.   
     
     
         3 . The dilution mechanism according to  claim 1 , further comprising a correlation data storage unit that stores correlation data indicating a correlation between the conductivity of the diluted sample and the particle concentration of the sample, wherein
 the concentration calculation unit is configured to calculate the concentration of the particles contained in the diluted sample using the correlation data.   
     
     
         4 . The dilution mechanism according to  claim 1 , wherein the concentration adjusting unit is a fluid control valve provided to at least one of the sample line and the dilution line. 
     
     
         5 . The dilution mechanism according to  claim 1 , wherein the sample line is configured to collect the sample from a manufacturing system used in a predetermined manufacturing process. 
     
     
         6 . A particle size distribution measurement system comprising:
 the dilution mechanism according to  claim 1 ; and   a particle size distribution measurement device that measures a particle size distribution of particles contained in the sample diluted by the dilution mechanism, using a dynamic light scattering technique.   
     
     
         7 . The particle size distribution measurement system according to  claim 6 , wherein the sample contains a chemical component resulting a correlation between the concentration of particles contained in the sample and the conductivity of the sample. 
     
     
         8 . A particle size distribution measurement method for measuring a particle size distribution using a dynamic light scattering technique, the method comprising:
 a step of guiding a sample containing particles to a particle size distribution measurement device through a sample line;   a step of merging a diluent to the sample line;   a step of adjusting a concentration of the particles contained in the diluted sample using a concentration adjusting unit;   a step of measuring conductivity of the diluted sample using a conductivity measuring unit; and   a step of controlling the concentration adjusting unit to bring the conductivity measured by the conductivity measuring unit or to bring a conductivity-related value that is a value calculated from the conductivity, to a predetermined target value.   
     
     
         9 . A non-transitory computer readable medium storing a particle size distribution measurement program used in a particle size distribution measurement system comprising:
 a particle size distribution measurement device that measures a particle size distribution using a dynamic light scattering technique; a sample line that guides a sample containing particles to the particle size distribution measurement device;   a dilution line that merges with the sample line and through which a diluent flows;   a concentration adjusting unit that adjusts a concentration of the particles in the diluted sample; and   a conductivity measuring unit that measures conductivity of the diluted sample, the program causing a computer to exhibit a function as a control unit that controls the concentration adjusting unit to bring the conductivity measured by the conductivity measuring unit or to bring a conductivity-related value that is a value calculated from the conductivity, to a predetermined target value.